How to design, build and test small liquid-fuel rocket engines

The rocket engine is a relatively simple device in which propellants are burned and the resulting high pressure gases are expanded through a specially shaped nozzle to produce thrust. Gas pressurized propellant tanks and simple propellant flow controls make operation of a small liquid-fuel rocket engine about as simple as operating an automobile engine. Why then do so many amateur rocket engines fail or cause injury? ROCKETLAB cannot assume responsibility, in any manner whatsoever, for the use readers make of the information presented herein or the devices resulting therefrom.